The invention relates generally to proximity probes, and more particular, to an apparatus and method for operating a proximity probe for detecting a proximity to a probe target in which the proximity probe is wirelessly coupled to a power source.
During use, known proximity probes are used to detect a distance between the proximity probe and a target object, such as a turbine shaft. The data obtained by the probe can be used to accurately measure the vibration that the shaft is experiencing. Such vibrations can be indicative of wear of the bearing or the shaft, or of an unbalanced shaft.
Some known proximity probes are eddy current (EC) devices that measure the interaction between an electromagnetic field generated by the EC device and the target object being measured. At least some of such known EC devices include a sensing coil that generates a magnetic field. When the sensing coil is positioned adjacent to a conductive component, an eddy current is generated across a surface of the component. The EC device measures the generated eddy current and converts the measurement to an electrical signal that is transmitted to a device that interprets the measurement. Moreover, known EC devices include physical wires that couple the EC device to a power supply and for connections that enable the transmission of the electrical signals representing the EC device's measurements.
At least some other known proximity probes use microwaves to detect the proximity of the target object to the probe. Such probes use an antenna, such as patch antennas or micro-strip antennas, to transmit the microwaves. Similar to known EC probes, microwave proximity probes also include physical wires to enable connections to a power supply and/or connections to enable the transmission of the electrical signals representing the proximity probe's measurements. Similar to the function of a transformer, some known electronic devices are capable of receiving electrical power wirelessly, but use magnetic wire wound coils to magnetically couple with a second coil that is physically connected to a power source. Generally, known magnetic wire wound coils are larger than the antennas used to transmit and/or receive microwave signals, and as such, such coils may be expensive to manufacture and may increase the mass of the device in which the coils are installed.
FIG. 1 is a block diagram illustrating an exemplary known proximity probe system 100 that includes a known eddy current (EC) proximity probe 102. Known state-of-the-art probes 102 include physical power wires 104 that enable probe 102 to be coupled to a power source 106 and/or physical data wires 108 used to transmit collected data relative to the distance measured between a metallic target object 110 and EC proximity probe 102 to a data collection receiver 112. Other state-of-the-art known probes are microwave probes 114 that use transmitting and receiving microwave antennas to measure the distance between microwave probes 114 and a target object 116. With such probes, target object 116 may be metallic, non-metallic, or any other material that is detectable by microwave probe 114. Similar to EC probes 102, known microwave probes 114 also require physical power wires 104 to receive power from power source 106 and/or physical data wires 108 to transmit data representing the distance between microwave probes 114 and target objects 116.
Lastly, known state-of-the-art proximity probes that need physical wires to provide electrical power and/or carry data transmission can require complex wiring schemes. Over time, such wiring and associated electrical connections may fail. Moreover, the physical constraints of wiring can limit the areas that the proximity probes may be positioned relative to a target object.